1. The problem statement, all variables and given/known data I'm trying to find the capacitance of a system of 3 concentric hollow cylinders. The first cylinder has radius R, the second radius 2R, the third radius 3R. Cylinders 1 and 3 are connected by a wire. In total, they have charge +λ, and the second cylinder has charge -λ. The cylinders are infinitely long. 2. Relevant equations Ehollow cylinder = (1 / 2πεo)*(Q / RL) C= Q / V 3. The attempt at a solution Since cylinders 1 and 3 are connected by the wire, the charge will distribute evenly according to surface area. Cylinder 3 has 3 times as much surface area, so it will have charge 3λ/4 (And Cylinder 1 will have charge λ/4). I know that to solve this problem I must integrate the electric field to find the potential, and use that in C=Q/V to find capacitance. However, I don't really understand what the limits of my integration are. The outer cylinders are positive, so their electric fields point inwards to the middle cylinder. Do I account for their opposite directions (cancelling each other out partially)? Do I just integrate E from R to 3R? Do I need to multiply two oppositely signed integrals by the proportion of charge? I was thinking of multiplying ∫E from R to 2R by λ/4, and multiplying ∫E from 2R to 3R by 3λ/4, then subtracting those. My believe my biggest trouble is that I don't understand how to deal with more than 2 surfaces for capacitor (and I can't find anything to help me online).